1. Field of Invention
The invention relates to an optical transceiver packaging for receiving and transmitting optical signal. More particularly, the invention pertains to an optical transceiver packaging convenient for manufacturing and assembly.
2. Related Art
The optical transceiver module is installed in an electronic device to emit or receive optical signals through optic fibers. Basically, the optical transceiver module has a case 11, a base 12, a receiver optical subassembly (ROSA) 13, a transmitter optical subassembly (TOSA) 14, and a circuit board 15. With reference to FIG. 1, the base 12 supports the circuit board 15, and the case 11 covers the base 12. The circuit board 15 has the functions of transmitting/receiving electrical signal to/from TOSA/ROSA. The circuit board 15 is connected to the electronic device through its pins 151 so that the electronic device can transmit and receive optical signals via its transceiving terminal.
The circuit board 15 is parallel to the base 12, with the emitter 14 and the receiver 13 installed on its front end for connecting with optic fibers. Since the circuit board 15 has both functions of transmission and reception, it is likely to have crosstalks, deteriorating the signal quality. Any error occurred to the circuit cannot be easily attributed to the reception or transmission. Furthermore, the elements on the circuit board 15 are limited by the size of the circuit board 15 to be placed fairly close to one another, resulting in serious crosstalk.
To solve the problem of crosstalks, the prior art has the functions of transmission and reception separately on two independent circuit boards. As shown in FIG. 2, the two circuit boards 16, 17 have the functions of transmitting and receiving optical signals and connect to the transmitter 14 and the receiver 13, respectively. This can reduce the problem of crosstalks. Moreover, once any error occurs to the system, one can easily identify where the problem is. However, since the two circuits 16, 17 are installed in parallel, an extra shielding design is needed to completely solve the crosstalk problem. As the whole optical transceiver module is small and the two circuit boards 16, 17 are shielded from each other, the circuit board assembly and its element testing and debugging are limited by the span of the two circuit boards.
The invention provides a packaging method for the optical transceiver module. It can solve the problems of EMI and crosstalks. The invention also efficiently utilizes the inner space of the module to achieve the goals of easy assembly, tests and manufacturing.
The disclosed packaging method for the optical transceiver module includes a base, a transmission unit, a receiving unit, and a case. The receiving unit and the transmission unit contain a circuit board, respectively. The base has two fixing positions for the installation of the two circuit boards. The two circuit boards are installed perpendicularly, with one parallel to the base while the other perpendicular. This design greatly reduces the problems of crosstalks and EMI. On the other hand, the base uses the design of a central beam, so that most of the circuit boards is exposed for convenient assembly and debugging. The base and the case are combined in a drawable way just like a matchbox. Therefore, invention can be easily assembled and difficult to be taken apart.